Field of the Invention
The present teaching relates to liquid jetting apparatuses jetting liquid.
Description of the Related Art
Japanese Patent Application Laid-open No. 2005-22190 discloses an ink jet head as a liquid jetting apparatus which jets ink from a plurality of nozzles respectively. This ink jet head includes a flow passage formation substrate in which a plurality of pressure chambers are formed, a nozzle plate which is joined to the flow passage formation substrate and in which the plurality of nozzles are formed to communicate respectively with the plurality of pressure chambers, and a plurality of piezoelectric elements arranged on the flow passage formation substrate to correspond respectively to the plurality of pressure chambers.
Each of the plurality of pressure chambers has a rectangular shape and is aligned in the flow passage formation substrate along a predetermined direction. The plurality of pressure chambers are covered by a vibration film (an elastic film). Further, the plurality of pressure chambers are in respective communication with a manifold which is formed in the flow passage formation substrate to extend in an alignment direction of the pressure chambers. From this manifold, the ink is supplied respectively to the plurality of pressure chambers.
Each of the piezoelectric elements corresponding to one of the pressure chambers has a piezoelectric layer and two electrodes (an individual electrode and a common electrode) arranged to interpose the piezoelectric layer there between. The individual electrode of each of the piezoelectric elements also has a rectangular shape similar to the pressure chambers, and is arranged over a central portion of the corresponding pressure chamber. A trace (a leading electrode) is connected to a longitudinal end of the individual electrode. The trace extends from the end of the individual electrode up to the outer side of the corresponding pressure chamber along a longitudinal direction of the corresponding pressure chamber. If a voltage is applied to the piezoelectric layer of the piezoelectric element through the trace, then a flexural deformation occurs in the vibration film so as to exert a pressure on the ink inside the corresponding pressure chamber.